Initially -compact spaces for large
Commentationes Mathematicae Universitatis Carolinae (1999)
- Volume: 40, Issue: 2, page 319-325
- ISSN: 0010-2628
Access Full Article
topAbstract
topHow to cite
topChristodoulou, Stavros. "Initially $\kappa $-compact spaces for large $\kappa $." Commentationes Mathematicae Universitatis Carolinae 40.2 (1999): 319-325. <http://eudml.org/doc/248413>.
@article{Christodoulou1999,
abstract = {This work presents some cardinal inequalities in which appears the closed pseudo-character, $\psi _c$, of a space. Using one of them — $\psi _c(X) \le 2^\{d(X)\}$ for $T_2$ spaces — we improve, from $T_3$ to $T_2$ spaces, the well-known result that initially $\kappa $-compact $T_3$ spaces are $\lambda $-bounded for all cardinals $\lambda $ such that $2^\lambda \le \kappa $. And then, using an idea of A. Dow, we prove that initially $\kappa $-compact $T_2$ spaces are in fact compact for $\kappa = 2^\{F(X)\}$, $2^\{s(X)\}$, $2^\{t(X)\}$, $2^\{\chi (X)\}$, $2^\{\psi _c(X)\}$ or $\kappa = \max \lbrace \tau ^+, \tau ^\{<\tau \}\rbrace $, where $\tau > t(p,X)$ for all $p \in X$.},
author = {Christodoulou, Stavros},
journal = {Commentationes Mathematicae Universitatis Carolinae},
keywords = {initially $\kappa $-compact space; $\kappa $-bounded space; closed pseudocharacter; cardinal inequalities; initially -compact space; -bounded space; closed pseudocharacter for a space},
language = {eng},
number = {2},
pages = {319-325},
publisher = {Charles University in Prague, Faculty of Mathematics and Physics},
title = {Initially $\kappa $-compact spaces for large $\kappa $},
url = {http://eudml.org/doc/248413},
volume = {40},
year = {1999},
}
TY - JOUR
AU - Christodoulou, Stavros
TI - Initially $\kappa $-compact spaces for large $\kappa $
JO - Commentationes Mathematicae Universitatis Carolinae
PY - 1999
PB - Charles University in Prague, Faculty of Mathematics and Physics
VL - 40
IS - 2
SP - 319
EP - 325
AB - This work presents some cardinal inequalities in which appears the closed pseudo-character, $\psi _c$, of a space. Using one of them — $\psi _c(X) \le 2^{d(X)}$ for $T_2$ spaces — we improve, from $T_3$ to $T_2$ spaces, the well-known result that initially $\kappa $-compact $T_3$ spaces are $\lambda $-bounded for all cardinals $\lambda $ such that $2^\lambda \le \kappa $. And then, using an idea of A. Dow, we prove that initially $\kappa $-compact $T_2$ spaces are in fact compact for $\kappa = 2^{F(X)}$, $2^{s(X)}$, $2^{t(X)}$, $2^{\chi (X)}$, $2^{\psi _c(X)}$ or $\kappa = \max \lbrace \tau ^+, \tau ^{<\tau }\rbrace $, where $\tau > t(p,X)$ for all $p \in X$.
LA - eng
KW - initially $\kappa $-compact space; $\kappa $-bounded space; closed pseudocharacter; cardinal inequalities; initially -compact space; -bounded space; closed pseudocharacter for a space
UR - http://eudml.org/doc/248413
ER -
References
top- Balogh Z., Dow A., Fremlin D.H., Nyikos P.J., Countable tightness and proper forcing, Bull. Amer. Math. Soc. 19 (1988), 295-298. (1988) Zbl0661.54007MR0940491
- Christodoulou S., Some topologies over a cardinal, Questions Answers Gen. Topology 10 (1992), 143-148. (1992) Zbl0782.54002MR1180472
- Dow A., On initially -compact spaces, in Rings of Continuous Functions; C. Aull ed., Lecture Notes in Pure and Applied Math. 95, 1985, pp.103-108. MR0789264
- Dow A., Compact spaces of countable tightness in the Cohen model, in Set Theory and Its Applications; LNM, 1401, 1989, pp.55-67. Zbl0684.54003MR1031765
- Hodel R., Cardinal functions I, in Handbook of Set-Theoretic Topology; K. Kunen and J.E. Vaughan eds., North-Holland, Amsterdam, 1984, pp.1-61. Zbl0559.54003MR0776620
- Juhasz J., Cardinal functions in topology - ten years later, Mathematical Centre Tracts 123, Mathematical Centrum - Amsterdam, 1980. Zbl0479.54001MR0576927
- Juhasz J., Cardinal functions II, in Handbook of Set-Theoretic Topology; K. Kunen and J.E. Vaughan eds., North-Holland, Amsterdam, 1984, pp.63-109. Zbl0559.54004MR0776621
- Koszmider P., Splitting ultrafilters of the thin-very tall algebra and initially - compactness, preprint.
- Stephenson R.M., Jr., Initially -compact and related spaces, in Handbook Set-Theoretic Topology; K. Kunen and J.E. Vaughan eds., North-Holland, Amsterdam, 1984, pp. 603-632. Zbl0588.54025MR0776632
Citations in EuDML Documents
topNotesEmbed ?
topTo embed these notes on your page include the following JavaScript code on your page where you want the notes to appear.